JP2654524B2 - LAN connection port switching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for switching ports when a port failure occurs in a system connected to a LAN.

[0002]

2. Description of the Related Art Conventionally, when communication is performed via a line, it is common practice to use a line switching device to switch to a channel in which no failure has occurred, in the event of a failure in a line interface portion on the DTE side such as a channel. It is. But LA
In N, even if a line switching device is attached, LA
All LANs may be disconnected, and all LANs
Cannot be applied to the line switching device.

As a method of changing a connection port to a LAN without switching a line, a data link protocol is provided for each port, and a multi-link protocol is used as a whole to cause the effect of a partial port failure. There are methods that do not.

There is also a method of changing routing information by using a network layer or the like higher than the data link layer to notify each other so as not to use a failed port.

[0005]

The above-described conventional port fault avoidance method has the following problems.

In the method using the multilink protocol, since the multilink protocol itself requires complicated control, it becomes difficult to develop corresponding software.
Furthermore, since the multilink protocol requires a connection-type protocol as a data link protocol, a storage area is required for each connection, and a large storage area is required for simultaneously communicating with a large number of partners.
It is difficult to provide a service such as broadcast that sends a notification to all members at once.

On the other hand, the method of notifying the switching of the failed port by the protocol of the upper layer has a problem that a delay for rewriting the routing information occurs immediately after the occurrence of the failure, which is not suitable for real-time communication.

An object of the present invention is to provide a LAN connection port switching method which can eliminate a transfer delay due to switching when a failure occurs in a port connected to the LAN.

[0009]

In order to solve the above problems, a first system of the present invention is a computer system having two or more connection ports for the same LAN. Send data on and L
LAN transmission / reception means for receiving data on the AN is provided for each port, and identical reception determination means for determining whether data received from each port is new data or already-received data is provided and transmitted. A transmission port selecting means for examining a port having the lowest waiting time among ports where no failure has occurred at the time, and requesting transmission therefrom, in accordance with the above-mentioned new received data received from the same reception determining means and a request of an application program. In the case where the protocol processing is performed and the transmission is performed, the transmission port selection unit has a protocol unit for requesting transmission, and when a failure occurs in a specific port, the remaining ports are used. .

A second system of the present invention is a computer system having two or more connection ports for the same LAN, transmitting data on the LAN through the ports and receiving data on the LAN. LAN transmission / reception means is provided for each port, and identical reception determination means for determining whether data received from each port is new data or already received data is provided, and no failure occurs during transmission. All ports have all port transmitting means for requesting transmission, perform protocol processing according to the request of the application program with new received data received from the same reception determining means, and when transmitting, all It has a protocol means for requesting transmission to a port transmission means, and when a failure occurs in a specific port, the remaining ports are used.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of a system based on the present invention, and FIG. 2 is a diagram showing the contents of protocol data.

Referring to FIG. 1, the system of the present invention comprises:
It is connected to LAN 1 by ports 2 and 3, and is connected to a group of partner systems. LAN transmission / reception means 4 and 5 are connected to each port, and are constituted by identical reception determination means 6, transmission port selection means 7 and protocol means 8.

Referring to FIG. 2, protocol data transferred according to the present invention includes a header section 21 of the MAC layer, a header section 22 of the present invention, and a header section 2 of an upper layer protocol.
3 and a user data section 24.

The MAC layer header section 21 is different for each LAN, but contains a destination MAC address 201 and a source MAC address 202.

The header section 22 of the present invention comprises a destination logical address 203, a source logical address 204, and a source sequence number section 205.

First, when a transmission request is generated from the application program 9, appropriate protocol processing is performed by the protocol means 8, and the upper layer header section 23 and the user data section 24 are assembled. It requests the transmission port selecting means 7 to transmit the assembled data, the logical address of the destination system, and the logical address of its own system.

The transmission port selecting means 7 sets the rise time of the own system and the sequence number of the transmission data from the rise time in the transmission source sequence number section 205, and further sets the destination logical address 203 and the transmission source logical address 204.

The transmission port selecting means 7 searches for a port in which no data is waiting to be transmitted and has no fault, and requests the LAN transmitting / receiving means corresponding to the port to transmit. The failed port is not searched, so
The transmission operation using only the port is performed.

In the LAN transmitting / receiving means, a broadcast address is set as the destination MAC address 201, its own MAC address is set as the transmission source MAC address, and the transmission is performed to the LAN 1.

The protocol data transmitted from the partner system in this manner is received from both ports 2 and 3 because the destination MAC address is a broadcast address.

The data received from the LAN transmission / reception means 4 and 5 is transferred to the same reception determination means 6.

The same reception judging means 6 first discards the reception data having the transmission source sequence number part 205 equal to or smaller than the reception sequence number reserved for each transmission source logical address.

If the source sequence number section 205 is larger than the current reception sequence number by one, the current reception sequence number is updated by one.

However, if the system rise time portion of the source sequence number is changed, the received data is validated, and the current reception sequence number is updated to the source sequence number portion 205 of the received data.

If the destination logical address does not indicate itself, the received data is discarded.

If the destination logical address indicates itself, the received data is transferred to the protocol means 8.

The protocol unit 8 performs a protocol process according to the received data, and transfers the received data to the application program 9 as needed.

In the above description, the first method of the present invention in which only one port is used at the time of transmission has been described. However, if a failure occurs in the transmission port immediately after requesting the transmission, it is necessary to wait for the recovery means of the upper protocol. Data cannot be sent correctly to the other party.

Therefore, instead of the transmission port selection means 7,
By using all-port transmitting means for transmitting data to all ports where no failure has occurred, it is possible to prevent such a failure from affecting transmission time. This is the second system of the present invention.

[0031]

As described in detail above, the L of the present invention
The connection port switching method of the AN does not require complicated control such as a multilink protocol and does not require a large storage area. Also, since the connection type or connectionless type can be used for the upper layer protocol of the present invention, a service such as a broadcast for notifying all members simultaneously is also possible.

Further, even when a failure occurs, there is no need to notify the switching of the failed port by a protocol of an upper layer, so that there is no delay for rewriting routing information immediately after the failure occurs, and real-time communication is realized. It is suitable.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a communication control unit of a system according to the present invention.

FIG. 2 is a diagram showing the contents of protocol data.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LAN 2, 3 LAN connection port 4, 5 LAN transmission / reception means 6 Same reception determination means 7 Transmission port selection means 8 Protocol means 9 Application program 21 MAC layer header section 22 Header section of the present invention 23 Upper layer header section 24 User data Part 201 destination MAC address part 202 source MAC address part 203 destination logical address part 204 source logical address part 205 source sequence number part

Claims (2)

(57) [Claims] In a computer system having two or more connection ports for the same LAN, LAN transmission / reception means for transmitting data on the LAN through the port and receiving data on the LAN is provided for each individual. Each port has the same reception determination means to determine whether the data received from each port is new data or already received data. It has a transmission port selecting means for checking the port with a small number and requesting transmission there, performs the above-mentioned protocol processing according to the new reception data received from the same reception determination means and the request of the application program, and when transmitting, It has protocol means to request transmission port selection means for transmission, and if a failure occurs in a specific port, it is necessary to use the remaining ports. Characteristic LAN connection port switching method. 2. In a computer system having two or more connection ports for the same LAN, LAN transmission / reception means for transmitting data on the LAN through the port and receiving data on the LAN is provided for each individual. Each port has the same reception determination means that determines whether the data received from each port is new data or data that has already been received, and transmits data to all ports that have not failed at the time of transmission. Requesting the port, perform the protocol processing in accordance with the request of the application program with the new reception data received from the same reception determination means, and when transmitting, send the transmission to the all port transmission means. A LAN which has a protocol means for making a request and uses a remaining port when a failure occurs in a specific port.
Connection port switching method.